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The Effects of Prior Resistance Exercise on Lipolysis and Fat Oxidation during Subsequent Endurance Exercise

2006; Lippincott Williams & Wilkins; Volume: 38; Issue: Supplement Linguagem: Inglês

10.1249/00005768-200605001-03144

1530-0315

Kazushige Goto, Naokata Ishii, Shuhei Sugihara, Toshitsugu Yoshioka, Kaoru Takamatsu, Robert R. Kraemer,

Exercise and Physiological Responses

PURPOSE: This study examined the effects of prior resistance exercise on the lipid metabolism during subsequent endurance exercise. METHODS: Ten healthy male subjects performed three types of exercise regimen on separate days: 1) endurance exercise only (E), 2) endurance exercise with prior resistance exercise and 20-min rest (RE20), and 3) endurance exercise with prior resistance exercise and 120-minrest (RE120). Resistance exercise consisted of six exercises, each with 3–4 sets at 10 repetition maximum. Endurance exercise was performed on cycle crgometer at approximately 50 % of the maximal oxygen uptake for 60 min. RESULTS: Measurements of blood lactate and hormone concentrations showed that the prior resistance exercise caused marked increases in lactate, norepinephrine (NE) and growth hormone (GH) concentrations. Before the endurance exercise, free fatty acids (FFA) concentration was higher in the RE120 trial than in the RE20 and E trials (P < 0.05), whereas concentrations of NE and GH were higher in the RE20 trial than in the RE120 and E trials (P < 0.05). During 60 min endurance exercise, the FFA and glycerol responses were greater in RE120 and RE20 trials than in the E trial (P < 0.05). Ketone body concentrations increased significantly in all trials (P < 0.05), with no significant difference between trials. In the RE20 trial, the concentration of GH after the resistance exercise showed significant correlations with mean concentrations of FFA (r=0.77, P < 0.01) and glycerol (r=0.92, P < 0.01) during the subsequent endurance exercise. During the endurance exercise, no significant difference was observed between trials when the oxygen uptake for the entire 60-min period of exercise was compared. However, the relative contribution of fat oxidation for energy production (calculated by the respiratory exchange ratio) was larger in the RE120 and RE20 trials than in the E trial (P < 0.05). CONCLUSION: These results suggest that lipolysis and fat oxidation during endurance exercise are enhanced by prior resistance exercise. Although both trials with long and short rest periods between resistance and endurance exercises caused similar effects, the involvement of different mechanisms was suggested. Supported by Grant from the Ministry of Education, Science, Sports and Culture of Japan.